Index: /trunk/src/VBox/Main/HardDiskImpl.cpp
===================================================================
--- /trunk/src/VBox/Main/HardDiskImpl.cpp	(revision 361)
+++ /trunk/src/VBox/Main/HardDiskImpl.cpp	(revision 362)
@@ -1543,5 +1543,5 @@
          * wait for it to finish. */
 
-        ComAssertRet (mStateCheckWaiters != ~0, E_FAIL);
+        ComAssertRet (mStateCheckWaiters != (ULONG) ~0, E_FAIL);
         ++ mStateCheckWaiters;
         alock.leave();
@@ -1558,4 +1558,6 @@
         }
         
+        AssertRCReturn (vrc, E_FAIL);
+
         /* don't touch aAccessError, it has been already set */
         return S_OK;